“Treasury is targeting yakuza-controlled companies to expose the underlying ownership of these seemingly legitimate companies,” said Sigal Mandelker, Treasury Under Secretary for Terrorism and Financial Intelligence in the statement. “We are ramping up pressure on this dangerous Japanese crime syndicate and local gang leaders who profit from everything from sexual exploitation, to weapons smuggling, and extortion.”

According to the department, the move is intended to protect the U.S. financial system from negative influence of TCOs and to expose the companies and the individuals behind them.

Morio was the Chief Executive Officer (CEO) of Yamaki K.K. He is currently a Yamaguchi-gumi executive. Tsuda, also an upper-level member of the gang, is the current CEO of the company.

Meanwhile, Takagi holds the same rank as Tsuda in the Yamaguchi-gumi. He also is the CEO of Toyo Shinyo Jitsugyo K.K. Mitsuyasu served as CEO of the company until 2016. After completing an executive position with the gang, he became an adviser to the Izu-gumi, which is a subsidiary.

The moves by the department freeze all of the assets of the members in the U.S. and generally prohibits persons in the U.S. from doing business with them, the office said.

Japan’s largest gang

According to the National Police Agency, the number of members in the Yamaguchi-gumi last year stood at 10,300, a figure that is nearly double that of the nation’s number-two gang, the Sumiyoshi-kai.

In the U.S., members of criminal syndicates from Japan have been accused of a number of crimes, including money laundering and trafficking in drugs. The department blacklisted gang members from Japan in 2015 and the following year.